Skip to main content

Trying to trim and get length then parse from string into Double

Please note these java.net forums are being decommissioned and use the new and improved forums at https://community.oracle.com/community/java.
4 replies [Last post]
MissMandy
Offline
Joined: 2013-03-26

I have been trying to trim the and get the length and parse the string into a double from what the user entered to no avail. Any help would be much appreciated. Please bear with me as I am still very new to Java.

So far what Ive done is asked the user to enter up to ten grades, I then added in there, if the user presses enter, then they are done entering. Then I would add up the grades and average them up and print it. I haven't added that coding in there yet, as I am still trying to trim, get length and parse the string into a double.

I know, It would make sense to read doubles from the user, but my instructor specifically asked that we read strings then convert to doubles if and only if the user entered a length > 0 of which I already established into my code.

So I am having troubles trying to trim, get length then parsing into doubles, if you could help me with that, that would be great!

import java.util.*;
import java.io.*;
public class Grades {

public static void main(String[] args)throws IOException {

   double validGrades = 0;
   double d = 0;
double total = 0;
final int SIZE = 10;
boolean exit = false;
int count = 0;
String gradesEntered;

BufferedReader bf = new BufferedReader(new InputStreamReader(System.in));
String[ ] grades = new String[SIZE];
String[ ] trimmedGradesEntered = new String[grades.length];

System.out.println("Please enter up to 10 grades and press enter to finish.");


while((count < SIZE) && (exit == false)){
System.out.print("Grade " + (++count) + ": ");
gradesEntered = bf.readLine( ) ;
if(gradesEntered.length() < 1){
exit = true;

}
}

}
}

Reply viewing options

Select your preferred way to display the comments and click "Save settings" to activate your changes.
zeeshanaayan07
Offline
Joined: 2013-08-11

woow . I appreciate your thinking

georget
Offline
Joined: 2005-07-06

use Double.valueof().

MackSix
Offline
Joined: 2013-03-27

How do you plan on using ENTER to exit the code when it is being used to enter a line? You should probably figure that out first. Then Look up Double.parseDouble() in the Java API documentation. ;)

dgodbey
Offline
Joined: 2006-10-27

Each primary data type has similar methods as described by MackSix for Double type.